You need to find ways to expose the cats to each other in a gradual fashion such that neither becomes afraid or aggressive. The presence of the other cat is always paired with something pleasant for both cats, such as a mouth-watering tidbit of food. Through this process, the cats come to associate "good things" with each other's presence. In this way the motivation for the aggressive behavior is decreased.

You need to find ways to expose the cats to each other in a gradual fashion such that neither becomes afraid or aggressive. The presence of the other cat is always paired with something pleasant for both cats, such as a mouth-watering tidbit of food. Through this process, the cats come to associate "good things" with each other's presence. In this way the motivation for the aggressive behavior is decreased.